What Will Happen to Michael Jackson's Children, and His Fortune?

The King of Pop is dead, and now begins what could turn into a legal battle over the custody of his three children — and what remains of his once-vast fortune.

Michael Jackson, who spent a lifetime and countless millions trying to recapture his lost childhood, has left his own children in legal limbo following his sudden death Thursday at a rented Los Angeles home, apparently of cardiac arrest.

Michael Jr. and Paris were in Jackson's sole custody following his 1999 divorce from Debbie Rowe, the children's biological mother. His third child, whom he affectionately called "Blanket," was born to an unknown surrogate who also waived her parental rights.

But it is not known whether Jackson ever wrote a will delineating who would have custody of his children or his estate when he died. He is survived by his parents, his ex-wife Rowe and his eight siblings. His first wife, Lisa-Marie Presley, is not expected to lay claim to any part of his estate.

Many lawyers and associates contacted by FOX News say they believe it was Jackson's intention for his children to pass to his mother, Katherine, the matriarch of the Jackson clan whom Jackson referred to as his "life and soul."

"I do not know of any kind of will or estate planning that Michael would have made," said Brian Oxman, a Jackson family lawyer. "But I know that he believed that if anything ever happened to him that his mother was a wonderful caretaker."

Debra Opri, a former Jackson family spokeswoman who represented photographer Larry Birkhead in his successful suit for custody of Birkhead's child with Anna Nicole Smith, agreed.

Katherine Jackson has been "a fantastic mother to a very large group, and I think these kids will be under her care and they're going to be OK," Opri said. "For a long time now things have been in place as to who would be raising the kids."

But the story may be complicated, as was always the case with the perennially beleaguered King of Pop. The judge who granted sole custody to Jackson in a 2005 dispute with Rowe reportedly reversed that decision over a technicality, according to TMZ, meaning Rowe could be first in line for custody of her biological children.

But Rowe, who reportedly was pushing for a larger settlement from Jackson during the 2005 hearings, stated clearly in court documents that she had no interest in taking her children.

"They're his kids. They're not my kids," she said. "I don't have any rights."

Some child advocates say Rowe's custody would prove detrimental to the children, and they believe she will never gain control of them.

"There's no judge on the planet that would give a woman like that custody of these children. She basically treated them like loaves of bread," said Wendy Murphy, a prosecutor and child advocate, who noted that 20 years of legal trends indicate that the contract will win out.

At stake is more than just family love. Jackson, who was believed to be $400 million in debt, also held giant assets, including the rights to his own mega-hits and a 50 percent stake in the company that owns the majority of the Beatles' catalog.

"Whoever does have custody of the children ultimately will have access to whatever remains of his estate," said Murphy. "Katherine, I think, if there is no will, will probably prevail because she's probably the relative that the courts will see as most appropriate."

But Katherine's claims could be put on hold if rumors of her poor health prove true and the courts determine she is not fit to care for her grandchildren, Murphy added.

Despite the potential potholes, some friends and associates said it was a cut-and-dried case that would not take long to resolve, even if Jackson had not written a will or left proper instructions for the maintenance of his estate.

"It is always complicated when there is not a will, but I can assure you that Michael Jackson crossed his T's and dotted his I's when it came to his children," Opri told FOXNews.com. "That means he made sure that there's something in writing saying who is going to take care of the kids and what was going to be done for them."

As sales of Jackson's records and memorabilia soar — Amazon.com reported a huge spike Friday over usual sales of his CDs and DVDs — it is possible that his very passing could help ensure that in death he eventually recovers from the massive debt he incurred in life, and provide financial comfort for his family.

But even then, Jackson might have thrown another fly in the ointment. Rumors persist that he planned to will the rights to the Beatles' songs to Paul McCartney, who never forgave Jackson when he bought the Fab Four's own songs out from under him in 1985.